Blasting apparatus



United States Patent 1 3,548,957

[72] Inventor Miron Abramovich Schegolevsky [56] References Cited a y ay; glg schad, 9/10, kv. 60, UNITED STATES PATENTS oscow, pp No. 740,3073,169,570 2/1965 Haag et a1 431/1 22 Filed June 26, 1968 FOREIGN PATENTS[45] Patented Dec. 22,1970 121,390 1962 U.S.S.R. 175/2 122,107 1964U.S.S.R. 175/4.5

Primary Examiner-Ernest R. Purser Atlorney--Waters, Roditi, Schwartz &Nissen [54] BLASTING APPARATUS 3 claims 2 Drawing Figs ABSTRACT: Adevice primarily intended for explosive [52] U.S. Cl. l75/4.5,destruction of hard rocks which employs a liquid high-explo- 102/22.102/23: 175/1 1; 299/13 sive three-component mixture. The constructivedesign of the [51] Int.Cl. E2 lc 37/12 apparatus enables the productionof a series of successive [50] Field of Search l75/2,4. 5, blastscontrollable by their strength and by the frequency of 11; 299/13;431/1, 91; 102/22, 23 their succession.

- sum 1 or 2 BLASTING APPARATUS The present invention relates toblasting apparatus employing liquid explosive material having for itscomponents fuel and an oxidizer, fired as a mixture underthe action ofliquid initiator.

Used as an oxidizer can be nitrogen tetroxide, nitric acid,tetranitromethane, and as fuel-kerosene, benzine, aniline, and toluene;as an initiator there can be used an eutectic alloy of potassium andsodium, and hydrazine.

The apparatuses of this type are known as jet-type blasting apparatuswhich can be used for destruction of rocks, for explosive forming undera layer of liquid in open dies and in other fields of technique wherethe energy of blast can be used.

From the earlier publications, in particular from the USSR authorscertificate No. 122,107, there is known a blasting apparatus usingliquid explosive and liquid initiator, and designed for boring holes.Said known apparatus is provided with a head having inlet channelsforseparate delivery of liquid components and liquid initiator suppliedto the liquid explosive for its detonation.

The reservoirs for liquid explosive components and initiator arearranged in the apparatus housing above the head with the channels,batching the liquid components and initiator being effected with the aidof valves provided at the inlet end of the channels and secured to aspring-loaded crossbeam. When the doses of liquid explosive arealternately fired, the shock wave forces out the crossbeam with thevalves and subsequent doses of explosive components and initiator passthrough clearances appearing after the displacement of valves and viathe channels to the hole face wherein the mixing of components and theirfiring is going on under the action of the initiator.

The known apparatuses do not provide for a possibility of control overthe working process. The supply and batching of components and initiatorare of occasional nature and depend on explosion parameters of each doseof the explosive. Stronger explosions bring about an increase of timerequired for opening the valves and for injecting a greater dose ofexplosive material into the hole face, which may finally bring about thebreakage of the blasting apparatus.

An object of the invention is to eliminate the above-mentioneddisadvantages of said known apparatus.

The present invention is aimed at the provision of a blasting apparatuswith a prompt control system facilitating the control over the explosionprocess.

Described hereinbelow is a blasting apparatus, mainly for destruction ofrocks, using liquid explosive materials and consisting of a head withchannels for delivery of the explosive components and the liquidinitiator, said channels being alternately closed by valves. Accordingto the invention, the apparatus comprises a pulse generator whichcontrols the drive of the valve closing the channel for delivery of theinitiator, and a sensing unit serving to register the blast, inparticular, an accelerometer which transmits a signal to the blastcontrol unit, said unit being operatively connected with the drives ofthe valves closing the component supply channels and with a drive of thevalve closing the channel for delivery of the initiator.

According to the invention, the blast control unit has a device forcontrolling the explosion strength and a device for counting misfires ina series on whose command there operate said valves cutting off thedelivery of components and initiator.

The invention makes it possible to steadily carry out the explosionprocess and facilitates the operation of the apparatus.

The invention is further explained by the following description of anexemplary embodiment thereof in'conjunction with the accompanyingdrawings, wherein:

FIG. 1 is a schematic diagram of the blasting apparatus; and

FIG. 2 is a block diagram of the blasting apparatus control system,according to the invention.

Referring to FIG. 1, the blasting apparatus comprises reservoirs 1 and 2for fuel and oxidizer which are the components of liquid explosivematerial, and reservoir 3 for li uid initiator, all respectivelyconnected by pipelines 4, 5 an 6 with apparatus head 7. Fuel andoxidizer are delivered from reservoirs 1 and 2 to apparatus head 7 withthe aid of pumps 8 and 9, and the initiator is supplied from reservoir 3under the action of compressed air in receiver 10 connected withreservoir 3.

Head 7 is provided with outlet channels 11, 12 and 13 (FIG. 2) forseparate delivery of fuel, oxidizer and initiator, which channels areconnected with pipelines 4, 5 and 6 and can be closed by valves 14, 15and 16 mounted therein and provided with individual drives 17, 18 and19, e.g. with electromagnetic drives. It is evident that said valves canbe mounted on supply pipelines 4, 5 and 6.

While the apparatus is in operation, fuel and oxidizer flowcontinuously, while the initiator for firing the charge is deliveredperiodically.

To carry out the working process, the apparatus, as shown in FIG. 2,comprises pulse generator 20 controlling drive 19 of valve 16 servingfor delivery of theliquid initiator, blast-registering sensing unit 21,preferably an accelerometer secured on apparatus head 7. When fuel andoxidizer are mixed and the mixture is fired by the initiator, theretakes place a blast sensed by sensing unit 21 whose signal comes toblast control unit 22.

Unit 22 comprises device 23 for controlling the strength of blast, anddevice 24 counting misfires in a series and operatively connected withdrives 17, 18 and 19 of valves 14, 15 and 16.

Device 24 is necessary because several misfires in a row may bring aboutan accumulation of a large amount of liquid explosive material capableof breaking the apparatus. This device is supplied with a master pulsefrom generator 20 and with a signal from device 23 for controlling thestrength of a blast. in case, no signals come from sensing unit 21 thatthe blast has occured device 24 collects the data on unrealized masterpulses up to a certain value. When the number of misfires is greaterthan a certain value, device 24 sends a signal to drives 18, 17 and 19of valves 14, 15 and 16, which close channels 11, 12 and 13 in apparatushead 7, thus cutting off the delivery of explosive components and theinitiator.

Thus, the invention provides for the control over the explosion process,insures the safety of operation, and makes it possible to control thestrength of each blast.

lclaim:

l. A blasting apparatus using liquid explosive materials, comprising: ahead provided with channels for delivering explosive components and aliquid initiator; valves closing said channel; means for driving saidvalves; a pulse generator controlling the drive of the valve associatedwith the channel for delivery of the liquid initiator; a sensing unitserving to register a blast; a blast control unit operatively connectedwith said valve driving means, said blast control unit being actuated byreceipt of a signal from said blast-registering sensing unit.

2. A blasting apparatus as claimed in claim 1, wherein said blastcontrol unit comprises a device for controlling the strength of a blastand a device for serially counting misfires, the latter device operatingby sending a command for the operation of said valves cutting off thedelivery of explosive components and initiator.

3. A blasting apparatus as claimed in claim 1 wherein the sensing unitis an accelerometer.

